1. Using public api : Create a class containing country datatype
2. Using public api : create a object of the class
3. Using admin interface, edit the object :
  On the redirect page ( url /content/edit/57/f/eng-GB ) you'll get this warning:
  Warning: eZContentClass::versionHistoryLimit 	Nov 01 2012 10:53:19
  class integer parameter doesn't match any content class ID